This invention relates to a photochemical reaction system and, more particularly, to the use of a single polychromatic light source to simultaneously irradiate a plurality of photochemical reactions with different regions of the spectrum.
The use of radiant energy such as ultraviolet light for the initiation of chemical reactions is well-known. A principal application of such use of ultraviolet light is the initiation of free radical chain reactions such as halogenation. Further background information on photochemical reaction systems can be had by reference to the following comprehensive publications:
W.A. Noyes, Jr. et al, "Advances in Photochemistry," Interscience Publ., 1963-1974;
Fitzgerald, "Analytical Photochemistry and Photochemical Analysis," Marcel Dekker Inc., 1971;
Srinivasan, "Organic Photochemical Synthesis," Wiley Interscience, 1971;
Weissberger, "Technique of Organic Chemistry", Interscience Publishers, Vol. II, "Catalytic, Photochemical and Electrolytic Reactions," 1956, Vol. XIV, "Energy Transfer and Organic Photochemistry", 1969.
A major cost of carrying out photochemical processing on a large industrial scale is electricity. This is due to the fact that conventional photochemical reactions are carried out using only part of the light spectrum at a given time. That is, any given photochemical reaction system generally utilizes only a portion of the applied spectrum and the remaining portions are left unutilized. The excess radiation may be attenuated such as by absorption or interference filtration of the unused wavelengths. While a monochromatic light source may be useful for the study of reaction mechanisms, it is difficult to obtain the high intensity required for preparative photochemical work. In the latter case, a polychromatic radiation of high intensity is generally required. Hence, a photochemical reaction system which would more effectively utilize the total applied radiant energy of a polychromatic light source would provide significant advantages over present methods of irradiation.